This chapter analyzes ultrasound-based techniques for evaluating tubal patency, a critical diagnostic component in female infertility. Traditional methods—including X-ray hysterosalpingography (HSG) and laparoscopic chromopertubation—are contrasted with contemporary approaches such as hysterosalpingo-contrast sonography (HyCoSy) and 4D ultrasound imaging. HyCoSy is prioritized for its noninvasive nature, real-time visualization of tubal flow using contrast agents, and concurrent assessment of uterine morphology. The standardized 4D HyCoSy protocol is outlined, covering patient preparation, contrast administration, and diagnostic criteria for tubal obstruction, hydrosalpinx, and peritoneal spillage. Clinical applications span infertility diagnostics, postsurgical monitoring (e.g., tubal anastomosis), and treatment planning for conditions linked to pelvic inflammatory disease or endometriosis. Procedural safety considerations, including contrast-related adverse event management and optimal timing (postmenstrual, preovulatory phases), are emphasized. By integrating diagnostic accuracy with patient comfort, ultrasound-based methods like 4D HyCoSy represent a paradigm shift in reproductive medicine, reducing reliance on invasive techniques while maintaining clinical rigor.